At present, as the drugs orally administered, naked tablets, coated tablets, capsules, powders, granules, pills and aqueous drugs (solutions) have been put on the market. Then, the preparations for oral application include buccal tablets and mucosa-adhesive film preparations. However, these are ones in which the drugs are allowed to be absorbed through the mucous membranes in the oral cavity, or ones for the purpose of treatment of diseases in the oral cavity, and are not ones for the purpose of usual drug absorption into the digestive tracts. Almost all of these are contrived to continuously release the drugs, and no rapidly soluble ones have been known.
Drugs commercially available as merely film-shaped, tape-shaped or sheet-shaped ones, not adhesive to the mucous membranes in the oral cavity, are not found. However, as seen from documents (patents), (A) a sheet-shaped administration formation such as medicine, confectionery, other food, a cosmetic or an article similar thereto orally administered or incorporated, which comprises 20 to 60% by weight of at least one film forming agent, 2 to 40% by weight of at least one gel forming agent, 0.1 to 35% by weight of at least one active substance (drug) and further less than 40% by weight of at least one inactive filler, and rapidly decomposes in water (Toku-Kai-Hei (Japanese Unexamined Patent Publication) 7-100186), and (B) a tape having a tensile strength of at least 200 psi (about 14 kg/cm2), a drug/mm3 of 0.01 to 2 mg and an optimum solubility to the drug, and having a composition comprising about 10 to 40% by weight of a physiologically acceptable thermoplastic polymer, about 15 to 50% by weight of a saccharide, about 5 to 40% by weight of a physiologically acceptable plasticizer and about 0 to 20% by weight of a physiologically acceptable lubricant (Toku-Kai-Hei 5-220203) are known. Further, (C) a sheet-shaped solid pharmaceutical composition characterized in that a solution or a suspension containing a substance having physiologically active action by the existence thereof in slight amounts is printed on, spread on, sprayed on, or injected into a pharmaceutically acceptable sheet-shaped carrier (Toku-Kai-Hei 5-124954) is also known.
However, in the above-mentioned invention (A), it is described that “it is an object of this invention to provide an administration formation rapidly decomposing in water and individually formulated in a sheet form” (the publication, page 8, right column, [0028]), but what contrivance causes the formation to rapidly decompose is not described at all. Although a drug is obtained in Example 2, merely “the drug decomposes in the mouth” (the publication, page 10, left column, [0064]) is only described, and details such as for the time for decomposition of the drug decomposes are not clear. In this Example 2, the temperature is elevated to 80° C. in preparation, so that a considerable period of time is taken for cooling after mixing and the like, which causes a disadvantage in the manufacturing process. Further, in the above-mentioned invention (B), sorbitol (lubricant) is used as one useful to enhance speeds of disintegration and dissolution of the tape. However, it is described that “for further assisting dissolution, a disintegrating agent, for example, cross caramelose Na type A, can be used in an amount of not exceeding about 10% by weight”, and this is considered because the use of only sorbitol sometimes results in an insufficient disintegration rate. Furthermore, in this invention, the drug tape is mounted on a dispenser, so that it is necessary to have a definite tensile strength. Control for the tensile strength is therefore required in production, which is disadvantageous to efficiency in actual production. Still further, in the above-mentioned invention (C), the substance showing physiologically activity by the existence thereof in slight amounts (a drug: for example, 0.02 mg per unit, in the case of mestranol) is utilized. The drug is effectively used in such slight amounts, so that the solution or suspension of the drug is printed on, spread on, sprayed on, or injected into the sheet-shaped carrier. However, this is time-consuming and not economical. Then, with respect to one shown in FIG. 1 of the published specification, not only slights are provided, but also punching is performed with a punch, resulting in complication of the process.
An object of the invention is to economically provide a film preparation having no disadvantages observed in the above-mentioned known film preparations, that is to say, rapidly dissolved, simply produced and economically obtained.